Method Return Type of Id

Question

I have a method that should return an "Id" when it finds a record, but if it does not find a matching record then it can't return an Id. For example, I run a query on the Account object:

private static Id getID( String param ) {

 List<Account> accList = [SELECT Id FROM Account WHERE customField__c = : param ];
 if (accList.size() > 0 ) {
  return accList[0].Id;
 }
 else {
 }

}

My question is the code that calls the getId() method throws an error because when a record is not found I am not returning any Id back to the calling code, In a perfect world, I would have an Account record always that matched by criteria in the query, but this isn't the reality. How can I have the best of both worlds where when it does find a matching record it returns the Id, but when it doesn't I am not sure how to handle that.

Answer 1

Null is the value you're looking for. It means "no value". You can also optimize your code as follows:

private static Id getID( String param ) {
  for(Account record: [SELECT Id FROM Account WHERE customField__c = :param limit 1]) {
    return record.Id;
  }
  return null;
}

This gets rid of the empty list check.